Last week, the Rt Hon Phillip Hammond MP set out his Autumn Budget. As eye-catching promises such as scrapping Stamp Duty Land Tax for nearly all first-time homebuyers – something Bright Blue had been calling for – caught the headlines, other measures have seemingly slipped under the radar. One such ambition is to increase housing density in urban areas – which the Chancellor believes can be achieved through policies such as making it easier to convert retail land into housing, greater support for the use of compulsory purchase powers, and introducing minimum density requirements on new projects in city centres and around transport hubs.

In London, where the need for housing is perhaps most acute, Mayor Sadiq Khan has recently released a draft of ‘The London Plan’ – a strategy document for spatial development in the capital – in which numerous ideas for achieving higher-density housing, such as developing on brownfield sites and on surplus public sector land, were mooted.

A White Paper issued earlier this year by the Secretary of State for Communities and Local Government, the Rt Hon Sajid Javid MP, set out measures intended to rectify the problem of Britain’s low-density housing. It proposed policies such as making it easier for existing buildings to be extended upwards and allowing more flexibility in the planning application process. Density, it would appear, is something very much on the political agenda – and for good reason.

Land space is finite in a way many other resources are not, thus making it particularly important to utilise effectively. Almost 11% of Britain has already been built on, but within the nation’s towns and cities, such development has all too often been done inefficiently with regards to space. In London, for example, there are only 150 dwellings per hectare, and the average for England sees that number fall to just 42. In this respect, Britain ranks woefully against its international counterparts: New York manages to fit 480 homes into an equivalent area, and Hong Kong a staggering 775 dwellings. Whilst some of this discrepancy can be explained by consumer preference, it is doubtless that government regulations are a significant causal factor in Britain’s tendency for low-density development.

Denser living, better environment

Increasing the density of development in Britain would have obvious benefits for the natural world, most evidently in the way that simply less of it will have to be sacrificed to buildings. Consequently, more habitats and ecosystems can go undisturbed – allowing wildlife a precious chance to flourish. Limiting the extent to which development impinges upon habitats will be a welcome reprieve for Britain’s animal species, 56% of which have seen their numbers decline over recent decades.

But there are other environmental advantages associated with increasing population density. When towns and cities sprawl outwards, people living in them have to make invariably longer journeys, because whilst their jobs and livelihoods will remain centrally located, their homes will not. Longer journeys equal more time for vehicle exhausts to emit the dangerous pollutants which contribute to poor air quality and climate change. Moreover, when people are housed further away from where they need to be on a daily basis, more environmentally friendly forms of transportation – be that walking, cycling, or using public transport – may become less attractive. This would likely increase the amount of people using private vehicles, thereby exacerbating the problems of air pollution and climate change.

The benefits of more compact living are not solely environmental. Utilities and public services which have relatively high fixed costs, but relatively low marginal costs, are more economically viable to provide in areas of greater population density, because of the ability to exploit economies of scale (that is, when diminishing average costs are realised with the supply of one extra unit of good or service). One example of this could be a public transportation network, which, incidentally, would in turn have benefits for the environment if it acts as a disincentive to private vehicle travel, and frees up land space for nature by reducing the need for certain infrastructure such as purpose-built car parks.

It should be noted, however, that some environmental disadvantages exist with regards to density achieved primarily through high-rise developments. Studies suggest that taller buildings can be more energy intensive on a day to day basis, and often have greater amounts of ‘embodied energy’ within them because of the materials they must be made from – for instance, reinforced concrete and steel. Any impetus towards increasing density, therefore, should be done sensitively, with such concerns in mind.